Scanning modes of a CT device may include an axial scan and a helical scan. The axial scan refers to a scan in which a scanning bed firstly moves to a first scanning position, and then an X-ray tube begins emitting X-rays to perform scanning (hereinafter referred to as ray-emitting scan); when the scanning for the first scanning position is finished, the scanning bed moves to a second scanning position, and then the X-ray tube begins to perform the ray-emitting scan again. Therefore, scanning speed of the axial scan is relatively slow, and resolution of a reconstructed image obtained by the axial scan is relatively low in a movement direction (hereinafter referred to as z-direction) of the scanning bed.
The helical scan refers to a scan in which a scanning bed moves forward at a particular speed when a gantry of a CT device rotates. Therefore, scanning speed of the helical scan is relatively fast, and resolution of a reconstructed image obtained by the helical scan is relatively high in the z-direction. In the helical scan, the X-ray tube mounted on the gantry keeps emitting X-rays when the gantry rotates.
NEUSOFT MEDICAL SYSTEMS CO., LTD. (NMS), founded in 1998 with its world headquarters in China, is a leading supplier of medical equipment, medical IT solutions, and healthcare services. NMS supplies medical equipment with a wide portfolio, including CT, Magnetic Resonance Imaging (MRI), digital X-ray machine, ultrasound, Positron Emission Tomography (PET), Linear Accelerator (LINAC), and biochemistry analyser. Currently, NMS' products are exported to over 60 countries and regions around the globe, serving more than 5,000 renowned customers. NMS's latest successful developments, such as 128 Multi-Slice CT Scanner System, Superconducting MRI, LINAC, and PET products, have led China to become a global high-end medical equipment producer. As an integrated supplier with extensive experience in large medical equipment, NMS has been committed to the study of avoiding secondary potential harm caused by excessive X-ray irradiation to the subject during the CT scanning process.